


Waves

by streikoneko



Category: Free!
Genre: M/M, mermaid au
Language: English
Status: Completed
Published: 2014-07-11
Updated: 2014-07-11
Packaged: 2018-02-08 09:44:26
Rating: Mature
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 1,793
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/1936200
Author URL: https://archiveofourown.org/users/streikoneko/pseuds/streikoneko
Summary: <blockquote class="userstuff">
              <p>Rin never expected to care so much about his strange, finless ward. Mermaid AU I’m gonna be honest and just say that this is just porn without any plot. There’s a semblance of plot, but it’s really just smutty, dirty mermaid porn.</p>
            </blockquote>





	Waves

**Author's Note:**

> I’m going to start off my fanfiction career with porn. RinTori porn. Mermaid RinTori porn. Pretty solid step I must say. (Also, why is no one writing interspecies mermaid porn I am very disappointed)

I'm going to start off my fanfiction career with porn. RinTori porn. Mermaid RinTori porn. Pretty solid step I must say. (Also, why is no one writing interspecies mermaid porn I am very disappointed)

Title:Waves

Pairing: Rin x Nitori

Summary: Rin never expected to care so much about his strange, finless ward. Mermaid AU I'm gonna be honest and just say that this is just porn without any plot. There's a semblance of plot, but it's really just smutty, dirty mermaid porn. 

Rating: Mature, very mature, so mature that you may taste taxes

No one knew what to make of Nitori Aiichirou. From his inability to stay underwater for more than handful of minutes to his strange finlessness, he managed to perplex all the merfolk he met. Not that many came to meet the strange land dwelling mermaid anyways. There were too many other things for the merfolk to do usually, things more important than looking at the gillless wonder. 

Except for Rin. 

He had taken responsibility for the boy after seeing him floating atop the waves unconscious. For a moment he had thought the still body to be that of a seal breed, albeit extremely mutated. Nonetheless, he had gotten Makoto to help resuscitate the small creature. When its blue eyes had opened there had been a moment of groggy confusion from the being. And then screaming. Painful, ear splitting screams had filled the air as the now conscious creature had pointed to their fins and flukes in terror. 

The stranger hadn't been the only one screaming at the time. Makoto had cried out in horror when he had seen the lower half of the creature he had woken up move in a terrifyingly strange way. Rin had been slightly more composed. Only slightly. He had immediately tried to soothe his terrified friend by suggesting that the strange thing was just a fairy. 

A wingless fairy. 

A rather plain looking fairy. 

Needless to say, the orca hadn't believed him and honestly, Rin knew he was spewing desperate bullshit to clarify the strangeness that he had just seen. 

But then the strange creature had quickly run from them. It had been graceless, hardly befitting of sharing the name of the movement that the fairies seemed to enjoy doing so much when their wings got tired. Makoto had quickly swum off, still trembling from the sudden shock. Rin had stayed, staring at the little cave he saw the creature cowering inside. 

He curiosity had been piqued. Day after day, he had returned to the rocky slab protruding from the beach. He brought fish often, supposing that wherever this creature came from that the tradition of giving gifts was commonplace as well. Being as there was never any food when he came the next day, Rin had assumed that his gifts were being appreciated. It had taken two weeks for the little creature to come to him. 

A month later, he had found Ai, for that was what the creature called itself, to be a decent swimmer. He was no merfolk, but much more proficient than any fairy. The creature had told him that he was a species by the name of ''human''. They were strange beings. Flightless, furless, and finless, they relied on their flimsy looking legs to get where they needed to go. They couldn't hold their breath underwater nor could they handle changes in the weather very well without getting ill. 

And apparently their male genitalia were always out and dangling like noodles when not in use; which sounded mightily inconvenient to both him and those he spoke to about his new friend. Ai had blushed profusely when Rin had gently rubbed his knuckles against the appendage, seemingly confused and worried. He had asked a barrage of questions, seemingly baffled that such a sensitive place was left constantly exposed, especially on such a fragile creature as a human. 

A year later, they had found themselves in a strange, albeit fulfilling, relationship. Rin often wondered how he had come to start caring so much about this strange, lost boy. He continued to bring fish on a daily basis, occasionally hauling himself upon the sand to experience life the way his partner did. More often then not though, Ai would spend hours in the ocean with Rin and his friends. Nagisa especially enjoyed meeting Ai. The new creature factor had never seemed to fade away for the feathered mermaid, and their conversations were often filled with species information exchanges. Sometimes Rin found himself unable to believe that Ai was a completely other species suited for land, what with him being in the water so much.

Nitori couldn't believe he was fucking a mermaid. 

He had been swept off a boat while fishing with his dad and had awoken to two strange creatures hovering over him. After weeks, he had finally come to accept that mermaids were real. Mermaids, as well as a whole horde of fairy tale creatures. Sometimes the strangeness of it all made him sick for home. Sometimes it made him feel incredibly lucky. There were strange fruits that were so deliciously sweet he had been brought to tears a couple of times. The fish were always juicy, and everyone he had met was generally warm and welcoming. This strange place he had been brought to wasn't bad. Despite occasional pangs of homesickness, Nitori was happy. 

But whenever Rin was with him, he felt happiest. His grumpy and loving mermaid boyfriend had the tail and teeth of a shark, but had luckily skimped on the rough denticles that would have abraded Nitori's thighs raw. 

Sighing blissfully, he clenched those same thighs tighter around Rin's waist. “Rin,” he whined weakly as sharp fangs teasingly glided over his collarbone. “Hurry.”

“No,” came the amused response. “We only just started.” Flicking a slightly pointed tongue at the skin under his lover's slender jawline, Rin grinned. 

He thrust slowly into his little human, enjoying the moans and cries of pleasure filling the air. As Nitori gripped desperately to his shoulders, Rin reached down to rub his second clasper and Nitori's swollen penis together. A moan left his lips as the sensation of being buried deep inside his partner's tight body mixed with that of their thick organs rubbing fervently against one another. 

“Rin,” his name left Nitori's lips like a soft, desperate prayer. Slender hips bucked against the mermaid's tail, toes curling against the smooth skin as he panted for air. “Please,” he begged desperately. “Rin, let me cum.”

“Being demanding are we?” Rin asked teasingly as he gave a wild buck into Nitori's clenching ass, pulling a cry from the startled boy. The mermaid gently nibbled at an exposed shoulder. “I'm gonna have to punish you for that.” 

“No,” Nitori whimpered weakly. “Don't tease me like that.” He rocked his hips desperately, valiantly attempting to fuck himself on the clasper buried deep inside his ass. 

Rin loved seeing Nitori like this. Weak and desperate, begging to be fucked. He hadn't expected to enjoy being a teasing lover so much. But when Nitori had been on the verge of tears that first time, his tight little asshole clenching around him desperately as he pleaded with him, Rin hadn't been able to resist torturing the cute creature a little more often. And he knew Nitori enjoyed it as well. The slender human always came harder, always cried out louder in pleasure when Rin finally let him reach his peak. His mate's body would go limp afterwords, and he'd cuddle himself to sleep. 

So Rin waited, his claspers aching, and his hips restrained from bucking only by sheer will. Finally, Nitori stoped rutting against him. Teary blue eyes gazed into his as those soft pink lips of his partners opened. The first time he said the words, they're inaudible and Ai's face is aflame. The second time around, the sentence is a bit more coherent, even though the speaker remained a blushing mess. 

“Please...please fuck me... Rin-senpai.”

Hands gripping onto Nitori's soft butt cheeks- sweet heavens he loved those soft little mounds- Rin thrust upwards into agonizingly pleasurable heat. His partner's loud cry of ecstasy only spurred the shark on. As one of his claspers drove into that welcoming ass, the other rubbed occasionally against Ai's stiff cock. Refusing to have any of that, he began to order Ai. 

“Grab your cock and my clasper,” he demanded, “hold them together.”

“I- I can't!” Nitori whimpered. “It's already too much.”

“Ai,” Rin growled, “Hold us together while I fuck you.”

When those hands finally took hold, fingers pushing the two sex organs together, Rin began to hump his human furiously. Nitori dug his fingers into his mate's muscular back. It was all too much, and yet not enough. The feel of having Rin both inside of him and rubbing against him made his legs weak. He needed so badly to cum, and yet it felt so good to be fucked mercilessly that he didn't want to end the pleasure. 

“Senpai, I'm gonna cum,” he wailed, hand tightening it's grip on their swollen members. The friction got rougher, pulling a rough moan from his shark. 

“Go ahead, I've got you” Rin said as he swelled even larger inside of Nitori, the thick clasper's tip increasing in size and rubbing mercilessly against his prostate. Grasping fingers held the pleasure weakened boy steady.

Ai wailed as he came, his semen spurting into the ocean. His ass tightened around his lover; dull nails clawed into his Rin's strong mermaid skin as he rode out his orgasm. Rin continued to thrust, extending his orgasm until the slender man was all but begging his shark to fill him with semen. 

Sharp teeth clamp onto sun tanned shoulders as Rin came with a final hard thrust. His cum filled Nitori's ass just as the flared end of his clasper gently extended to hold him in place. His body was claiming Ai again, marking the human as his. The air was silent save for the gentle lapping of waves and the panting of intertwined lovers. 

They both sighed and looked at each other with gentle smiles as the clasper buried in Ai finally began to release itself from the tight muscle surrounding it. Rin kissed him warmly Humming softly, he held the body of his mate close. Ai cuddled against his partner's heat, an exhausted yawn escaping him. He pressed a loving kiss to the shark's neck Closing his eyes, the exhausted boy drifted off to sleep. 

“Goodnight, Ai.” Rin murmured gently. 

A quiet murmur in return brought a smile to the redhead's lips. Cradling his precious cargo close, Rin swam carefully to shore, accompanied only by soft snores and the sound of stirring waves.

**Author's Note:**

> I am by no means a marine biologist. But what I do have is a very certain set of useless knowledge, and shark penis/clasper knowledge is part of it.


End file.
